Buggy code:
abstract class MobileServiceTableBase implements MobileServiceTableSystemPropertiesProvider { public static final String TABLES_URL = "tables//" ; protected static final String SystemPropertyPrefix = "__" ; protected static final String SystemPropertiesQueryParameterName = "__systemproperties" ; protected static final TreeMap < String , MobileServiceSystemProperty > SystemPropertyNameToEnum ; protected static final String VersionSystemPropertyName = MobileServiceTableBase . getSystemPropertyString ( Version ) ; protected static final List < String > IdProperties ; protected MobileServiceClient mClient ; protected String mTableName ; protected EnumSet < MobileServiceSystemProperty > mSystemProperties = EnumSet . noneOf ( MobileServiceSystemProperty . class ) ; protected EnumSet < MobileServiceFeatures > mFeatures = EnumSet . noneOf ( MobileServiceFeatures . class ) ; public MobileServiceTableBase ( String name , MobileServiceClient client ) { } public void addFeature ( MobileServiceFeatures feature ) { } public String getTableName ( ) { } public EnumSet < MobileServiceSystemProperty > getSystemProperties ( ) { } public void setSystemProperties ( EnumSet < MobileServiceSystemProperty > systemProperties ) { } protected MobileServiceClient getClient ( ) { } public ListenableFuture < Void > delete ( Object element ) { } public void delete ( Object element , TableDeleteCallback callback ) { } public ListenableFuture < Void > delete ( Object elementOrId , List < Pair < String , String > > parameters ) { } public void delete ( Object elementOrId , List < Pair < String , String > > parameters , final TableDeleteCallback callback ) { } protected JsonObject patchOriginalEntityWithResponseEntity ( JsonObject originalEntity , JsonObject newEntity ) { } protected Object getObjectId ( Object elementOrId ) { } protected void updateIdProperty ( final JsonObject json ) throws IllegalArgumentException { } protected boolean isValidTypeId ( JsonElement element ) { } protected void validateId ( final Object elementOrId ) { } protected Object validateId ( final JsonObject element ) { } protected boolean isStringType ( Object o ) { } protected String getStringValue ( Object o ) { } protected boolean isValidStringId ( String id ) { } protected boolean isDefaultStringId ( String id ) { } protected boolean containsControlCharacter ( String s ) { } protected boolean containsSpecialCharacter ( String s ) { } protected boolean isNumericType ( Object o ) { } protected long getNumericValue ( Object o ) { } protected boolean isValidNumericId ( long id ) { } protected boolean isDefaultNumericId ( long id ) { } public List < Pair < String , String > > addSystemProperties ( EnumSet < MobileServiceSystemProperty > systemProperties , List < Pair < String , String > > parameters ) { } protected static JsonObject removeSystemProperties ( JsonObject instance ) { } protected static String getVersionSystemProperty ( JsonObject instance ) { } protected static String getEtagFromValue ( String value ) { } protected static String getValueFromEtag ( String etag ) { } private static String getSystemPropertiesString ( EnumSet < MobileServiceSystemProperty > properties ) { } private static String getSystemPropertyString ( MobileServiceSystemProperty systemProperty ) { } protected static < F > EnumSet < MobileServiceSystemProperty > getSystemProperties ( Class < F > clazz ) { } protected static < F > Class < ? > getIdPropertyClass ( Class < F > clazz ) { } protected static < F > boolean isIntegerClass ( Class < F > clazz ) { } protected static Throwable transformHttpException ( Throwable exc ) { if ( exc instanceof MobileServiceException ) { MobileServiceException msExcep = ( ( MobileServiceException ) ( exc ) ) ; if ( ( ( ( msExcep . getResponse ( ) ) != null ) && ( ( msExcep . getResponse ( ) . getStatus ( ) ) != null ) ) && ( ( ( msExcep . getResponse ( ) . getStatus ( ) . getStatusCode ( ) ) == 412 ) || ( ( msExcep . getResponse ( ) . getStatus ( ) . getStatusCode ( ) ) == 409 ) ) ) { String content = msExcep . getResponse ( ) . getContent ( ) ; JsonObject serverEntity = null ; if ( content != null ) { serverEntity = new JsonParser ( ) . parse ( content ) . getAsJsonObject ( ) ; } if ( ( msExcep . getResponse ( ) . getStatus ( ) . getStatusCode ( ) ) == 412 ) { return new MobileServicePreconditionFailedExceptionBase ( msExcep , serverEntity ) ; } if ( ( msExcep . getResponse ( ) . getStatus ( ) . getStatusCode ( ) ) == 409 ) { <START_BUG> return new MobileServiceConflictExceptionBase ( msExcep , serverEntity ) ; <END_BUG> } } } return exc ; } No newline ; at end ; of file ; }

Fix:
return new MobileServiceConflictExceptionBase ( msExcep , null ) ;